static int cbm_write(struct exfat_dev* dev)
{
uint32_t allocated_clusters =
DIV_ROUND_UP(cbm.get_size(), get_cluster_size()) +
DIV_ROUND_UP(uct.get_size(), get_cluster_size()) +
DIV_ROUND_UP(rootdir.get_size(), get_cluster_size());
size_t bitmap_size = DIV_ROUND_UP(allocated_clusters, CHAR_BIT);
bitmap_t* bitmap = malloc(BMAP_SIZE(bitmap_size));
size_t i;
if (bitmap == NULL)
{
exfat_error("failed to allocate bitmap of %zu bytes",
BMAP_SIZE(bitmap_size));
return 1;
}
memset(bitmap, 0, BMAP_SIZE(bitmap_size));
for (i = 0; i < bitmap_size * CHAR_BIT; i++)
if (i < allocated_clusters)
BMAP_SET(bitmap, i);
if (exfat_write(dev, bitmap, bitmap_size) < 0)
{
free(bitmap);
exfat_error("failed to write bitmap of %zu bytes", bitmap_size);
return 1;
}
free(bitmap);
return 0;
}
int exfat_flush(struct exfat* ef)
{
if (ef->cmap.dirty)
{
if (exfat_pwrite(ef->dev, ef->cmap.chunk,
BMAP_SIZE(ef->cmap.chunk_size),
exfat_c2o(ef, ef->cmap.start_cluster)) < 0)
{
exfat_error("failed to write clusters bitmap");
return -EIO;
}
ef->cmap.dirty = false;
}
return 0;
}
/*
* Reads one entry in directory at position pointed by iterator and fills
* node structure.
*/
static int readdir(struct exfat* ef, const struct exfat_node* parent,
struct exfat_node** node, struct iterator* it)
{
int rc = -EIO;
const struct exfat_entry* entry;
const struct exfat_entry_meta1* meta1;
const struct exfat_entry_meta2* meta2;
const struct exfat_entry_name* file_name;
const struct exfat_entry_upcase* upcase;
const struct exfat_entry_bitmap* bitmap;
const struct exfat_entry_label* label;
uint8_t continuations = 0;
le16_t* namep = NULL;
uint16_t reference_checksum = 0;
uint16_t actual_checksum = 0;
uint64_t real_size = 0;
*node = NULL;
for (;;)
{
if (it->offset >= parent->size)
{
if (continuations != 0)
{
exfat_error("expected %hhu continuations", continuations);
goto error;
}
return -ENOENT; /* that's OK, means end of directory */
}
entry = get_entry_ptr(ef, it);
switch (entry->type)
{
case EXFAT_ENTRY_FILE:
if (continuations != 0)
{
exfat_error("expected %hhu continuations before new entry",
continuations);
goto error;
}
meta1 = (const struct exfat_entry_meta1*) entry;
continuations = meta1->continuations;
/* each file entry must have at least 2 continuations:
info and name */
if (continuations < 2)
{
exfat_error("too few continuations (%hhu)", continuations);
goto error;
}
if (continuations > 1 +
DIV_ROUND_UP(EXFAT_NAME_MAX, EXFAT_ENAME_MAX))
{
exfat_error("too many continuations (%hhu)", continuations);
goto error;
}
reference_checksum = le16_to_cpu(meta1->checksum);
actual_checksum = exfat_start_checksum(meta1);
*node = allocate_node();
if (*node == NULL)
{
rc = -ENOMEM;
goto error;
}
/* new node has zero reference counter */
(*node)->entry_cluster = it->cluster;
(*node)->entry_offset = it->offset;
init_node_meta1(*node, meta1);
namep = (*node)->name;
break;
case EXFAT_ENTRY_FILE_INFO:
if (continuations < 2)
{
exfat_error("unexpected continuation (%hhu)",
continuations);
goto error;
}
meta2 = (const struct exfat_entry_meta2*) entry;
if (meta2->flags & ~(EXFAT_FLAG_ALWAYS1 | EXFAT_FLAG_CONTIGUOUS))
{
exfat_error("unknown flags in meta2 (0x%hhx)", meta2->flags);
goto error;
}
init_node_meta2(*node, meta2);
actual_checksum = exfat_add_checksum(entry, actual_checksum);
real_size = le64_to_cpu(meta2->real_size);
/* empty files must be marked as non-contiguous */
if ((*node)->size == 0 && (meta2->flags & EXFAT_FLAG_CONTIGUOUS))
{
exfat_error("empty file marked as contiguous (0x%hhx)",
meta2->flags);
goto error;
}
/* directories must be aligned on at cluster boundary */
if (((*node)->flags & EXFAT_ATTRIB_DIR) &&
(*node)->size % CLUSTER_SIZE(*ef->sb) != 0)
{
exfat_error("directory has invalid size %"PRIu64" bytes",
(*node)->size);
goto error;
}
--continuations;
break;
case EXFAT_ENTRY_FILE_NAME:
if (continuations == 0)
{
exfat_error("unexpected continuation");
goto error;
}
file_name = (const struct exfat_entry_name*) entry;
actual_checksum = exfat_add_checksum(entry, actual_checksum);
memcpy(namep, file_name->name,
MIN(EXFAT_ENAME_MAX,
((*node)->name + EXFAT_NAME_MAX - namep)) *
sizeof(le16_t));
namep += EXFAT_ENAME_MAX;
if (--continuations == 0)
{
/*
There are two fields that contain file size. Maybe they
plan to add compression support in the future and one of
those fields is visible (uncompressed) size and the other
is real (compressed) size. Anyway, currently it looks like
exFAT does not support compression and both fields must be
equal.
There is an exception though: pagefile.sys (its real_size
is always 0).
*/
if (real_size != (*node)->size)
{
char buffer[UTF8_BYTES(EXFAT_NAME_MAX) + 1];
exfat_get_name(*node, buffer, sizeof(buffer) - 1);
exfat_error("`%s' real size does not equal to size "
"(%"PRIu64" != %"PRIu64")", buffer,
real_size, (*node)->size);
goto error;
}
if (actual_checksum != reference_checksum)
{
char buffer[UTF8_BYTES(EXFAT_NAME_MAX) + 1];
exfat_get_name(*node, buffer, sizeof(buffer) - 1);
exfat_error("`%s' has invalid checksum (0x%hx != 0x%hx)",
buffer, actual_checksum, reference_checksum);
goto error;
}
if (fetch_next_entry(ef, parent, it) != 0)
goto error;
return 0; /* entry completed */
}
break;
case EXFAT_ENTRY_UPCASE:
if (ef->upcase != NULL)
break;
upcase = (const struct exfat_entry_upcase*) entry;
if (CLUSTER_INVALID(le32_to_cpu(upcase->start_cluster)))
{
exfat_error("invalid cluster 0x%x in upcase table",
le32_to_cpu(upcase->start_cluster));
goto error;
}
if (le64_to_cpu(upcase->size) == 0 ||
le64_to_cpu(upcase->size) > 0xffff * sizeof(uint16_t) ||
le64_to_cpu(upcase->size) % sizeof(uint16_t) != 0)
{
exfat_error("bad upcase table size (%"PRIu64" bytes)",
le64_to_cpu(upcase->size));
goto error;
}
ef->upcase = malloc(le64_to_cpu(upcase->size));
if (ef->upcase == NULL)
{
exfat_error("failed to allocate upcase table (%"PRIu64" bytes)",
le64_to_cpu(upcase->size));
rc = -ENOMEM;
goto error;
}
ef->upcase_chars = le64_to_cpu(upcase->size) / sizeof(le16_t);
if (exfat_pread(ef->dev, ef->upcase, le64_to_cpu(upcase->size),
exfat_c2o(ef, le32_to_cpu(upcase->start_cluster))) < 0)
{
exfat_error("failed to read upper case table "
"(%"PRIu64" bytes starting at cluster %#x)",
le64_to_cpu(upcase->size),
le32_to_cpu(upcase->start_cluster));
goto error;
}
break;
case EXFAT_ENTRY_BITMAP:
bitmap = (const struct exfat_entry_bitmap*) entry;
ef->cmap.start_cluster = le32_to_cpu(bitmap->start_cluster);
if (CLUSTER_INVALID(ef->cmap.start_cluster))
{
exfat_error("invalid cluster 0x%x in clusters bitmap",
ef->cmap.start_cluster);
goto error;
}
ef->cmap.size = le32_to_cpu(ef->sb->cluster_count) -
EXFAT_FIRST_DATA_CLUSTER;
if (le64_to_cpu(bitmap->size) < DIV_ROUND_UP(ef->cmap.size, 8))
{
exfat_error("invalid clusters bitmap size: %"PRIu64
" (expected at least %u)",
le64_to_cpu(bitmap->size),
DIV_ROUND_UP(ef->cmap.size, 8));
goto error;
}
/* FIXME bitmap can be rather big, up to 512 MB */
ef->cmap.chunk_size = ef->cmap.size;
ef->cmap.chunk = malloc(BMAP_SIZE(ef->cmap.chunk_size));
if (ef->cmap.chunk == NULL)
{
exfat_error("failed to allocate clusters bitmap chunk "
"(%"PRIu64" bytes)", le64_to_cpu(bitmap->size));
rc = -ENOMEM;
goto error;
}
if (exfat_pread(ef->dev, ef->cmap.chunk,
BMAP_SIZE(ef->cmap.chunk_size),
exfat_c2o(ef, ef->cmap.start_cluster)) < 0)
{
exfat_error("failed to read clusters bitmap "
"(%"PRIu64" bytes starting at cluster %#x)",
le64_to_cpu(bitmap->size), ef->cmap.start_cluster);
goto error;
}
break;
case EXFAT_ENTRY_LABEL:
label = (const struct exfat_entry_label*) entry;
if (label->length > EXFAT_ENAME_MAX)
{
exfat_error("too long label (%hhu chars)", label->length);
goto error;
}
if (utf16_to_utf8(ef->label, label->name,
sizeof(ef->label) - 1, EXFAT_ENAME_MAX) != 0)
goto error;
break;
default:
if (entry->type & EXFAT_ENTRY_VALID)
{
exfat_error("unknown entry type 0x%hhx", entry->type);
goto error;
}
break;
}
if (fetch_next_entry(ef, parent, it) != 0)
goto error;
}
/* we never reach here */
error:
free(*node);
*node = NULL;
return rc;
}
